This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 10 |
| 1 | 15 |
| 2 | 25 |
| 3 | 45 |
| 4 | 85 |
| 5 | 165 |
| 6 | 325 |
| 7 | 645 |
| 8 | 1285 |
| 9 | 2565 |
| 10 | 5125 |
| 11 | 10245 |
| 12 | 20485 |
| 13 | 40965 |
| 14 | 81925 |
| 15 | 163845 |
| 16 | 327685 |
| 17 | 655365 |
| 18 | 1310725 |
| 19 | 2621445 |
| 20 | 5242885 |
| 21 | 10485765 |
| 22 | 20971525 |
| 23 | 41943045 |
| 24 | 83886085 |
| 25 | 167772165 |
| 26 | 335544325 |
| 27 | 671088645 |
| 28 | 1342177285 |
| 29 | 2684354565 |
| 30 | 5368709125 |
| 31 | 10737418245 |